Device for producing and withdrawing stacks of plastic bags, especially bags for automatic machines

ABSTRACT

The invention relates to a device for producing and withdrawing stacks of plastic bags, especially bags for automatic machines, in coordination with a gradually moving pin stack chain ( 4 ) from which the bag packages ( 6 ) are removed in a simplified and accelerated manner with the aid of a robot ( 16 ) that has a multifunctional hand ( 17 ) and automatically executes all essential manipulations and/or movements required for the formation and piling of the bag stacks and finally delivers them to an unloading station ( 62 ).

TECHNICAL FIELD

The invention relates to a device for producing and delivering of stacksof plastic bags, particularly bags for automated machines, with acrosscut-welding station for making welding seams in a double-layer foilweb of plastic material and separating the plastic bags from the web ofplastic material, optionally with a stamping station for producingstacking holes and an interlocking station, as well as a pin stackingconveyor with a stepwise movable pin stacking chain and a dischargestation which has a robot with a grip hand.

STATE OF THE ART

One problem with all bag-producing machines with a subsequently arrangedcollection and stacking device consists in that the output of thestacking, respectively collection device has to be adjusted to thecontinuously working bag fusion machine so that no interruption of thecycle occurs, while a finished bag is removed from the stacking stationand an empty stacking mechanism is introduced in the stacking station.In the production of the bag stacks it is known to fix the same by meansof wire brackets. For this purpose either the bag stack is lifted fromthe stacking pins of the pin stacking conveyor and with the now looselysuperimposed bags pushed over the legs of the wire brackets, or the legsof the wire brackets are inserted in slot-like recesses of the stackingpins of the pin stacking device, removing the bag stacks this way.Subsequently the bag stack has to be secured by safety plates,respectively rubber stoppers arranged on the bracket legs. Sometimes theseparate bag stacks are covered on both sides with paper strips,respectively intermediate paper layers. The manual removal of the bagstacks and the insertion of the wire brackets represents a comparativelybig physical effort for the operator, since the same, repetitive motionshave to be performed in a very short time, because of the relativelyhigh production speed.

To the extent that the use of wire brackets for holding the individualbags in the bag stack should be eliminated, an interlocking of theindividual plastic bags to a bag stack can already be achieved in thepin stacking conveyor, in that the bags are fused together by heat indefined locations, for instance in an area defined by perforations. Thisway a considerable simplification in the production of the plastic bagsis reached, since the removal of the bag stacks from the pin stackingconveyor can be performed much easier and finally also the packaging ofthe bags in cardboard boxes or the like is also simplified. However itstill remains the obligation of the operator to examine the quality ofthe bag packages and to prepare them for packaging for instance incardboard boxes.

From DE 38 34 115 can be seen that the concept of an automated removalprocess in the removal station by means of a robot is not new. Howeverin the end at that time it was considered much too complicated andexpensive to be put to use.

Indeed from EP 0 384 281 A1 a device for stacking bags on wire bracketshas been known, whereby the stacking device has stepwise movablestacking plates, onto which the bags can be stacked by means of wirebrackets. The positioning of the wire brackets on the stacking plates isdone by means of an automatically controlled and driven robot with agrip hand. An obvious additionally arranged robot with grip hand canfurthermore remove from the stacking plate the stacks interlocked bywire brackets and rubber stoppers and depose them on a transport belt.

DESCRIPTION OF THE INVENTION

It is the object of the invention to create a device of the mentionedkind suitable for producing and delivering stacks of plastic bags,particularly bags for automated machines, which further simplifies theand accelerates especially the removal and transfer of the bag stacks,so that an operator can limit his function only to the remaining qualitycontrol of the bag stack at an easily accessible location of themachine.

According to the invention this object is achieved in that the robot,which can be controlled in accordance with the relative motion of thepin stacking chain of the pin stacking conveyor, is equipped with amultifunctional program-controlled hand, and is positioned at the end ofthe pin stacking conveyor in such a manner that basically all thehandling and motion operations required for the formation and deliveryof the bag stacks can be performed. Thereby it is important for thestationarily mounted robot that the relative motion of the pin stackingchain be overlapped in longitudinal direction, and for the compensationof web vibrations also in transverse direction. With the means of theinvention it is insured that the operator has only to take care ofquality control, after which the finished bag packages can be packagedby the robot in for instance a cardboard box. Since the entire processof stack formation and delivery is performed by a single robot, themotions performed by the robot can be easily monitored by an operator,so that even at high production speeds, one operator—depending on thetype of bag—can also service, respectively supervise several machinesunder certain conditions.

This applies especially when the robot is substantially centrallylocated with respect to the longitudinal extent of the pin stackingconveyor and/or the robot is stationarily mounted in a support framearranged behind the pin stacking conveyor above the circulation plane ofthe pin stacking chain. Preferably the support frame can also bedesigned for receiving the auxiliary means for the stack formation, suchas wire brackets, safety plates, intermediate paper layers or the likeand/or rotatably driven bracket supply device and/or a unit having alocking and correcting function.

All the devices required for the bag stack formation and delivery can besimply and safely fastened to the multifunctional hand, which has afirst clamping bar and a second clamping bar adjustable in relation tothe first, when the multifunctional hand has a mounting plate made ofsandwich aluminum and a crossbeam adjustably guided in guide barsfastened to the mounting plates, which at the same time is designed tobe the support of the upper clamping bar. Furthermore the mounting platecan be used for the mounting of auxiliary devices, such as holdingdevice working with negative pressure for the safety plates, as well asintermediate paper layers and the like. Thereby the holding device forthe safety plates can be designed as a suction :head and the holdingdevice for the intermediate paper layers can be designed as a suctionfunnel.

For special purposes on the frontal side of the multifunctional handwire bracket holders can be provided, by means of which wire bracketswith bag packages are supplied to several machines arranged in asequence on a common transport delivery belt, preferably designed as anelevated transport chain. In this case the brackets can be picked upfrom a bracket magazine by means of a straightening and feeding tong andtransferred to the multifunctional hand of the robot.

To the extent that an interlocking of the bags by means of wire bracketsand safety plates can be dispensed with, by means of therobot-controlled multifunctional hand, mounted according to theinvention, it is possible to remove bag stacks interlocked throughfusion from the pin stacking conveyor and to deliver them to a cardboardbox or the like within a boxing station.

A further embodiment of the invention provides a collection device witha driving belt driven in a timed revolving manner which is arranged inthe discharge station within the motion range of the robot, on whichspaced-apart stacking plates each with a holding elements are fastened.Suitably it is further provided that the driving belt be guided aboutguide rollers which preferably arranged at a right angle to each other,at least one of the rollers being rotatably driven, and that further onthe side facing the pin stacking conveyor, a filling station and onfrontal side substantially transversely thereto a control and/or servicestation, as well as removal station on the side opposite to the drivingbelt are arranged.

The servicing is further simplified due to the fact that the stackingplates are fastened in an uneven number on the driving belt designed asa revolving chain and the latter are movable in a double timed stepalong the individual stations. In concrete execution a preparation ofthe stacking plates takes place starting from a bag stack receivingposition in the filling station in a single timed step in a followingstart position, whereby in the holding element of the stacking plate awire bracket, as well as optionally an inner intermediate layer, forinstance in the form of a paper strip or a cardboard sheet, can besuspended in the wire bracket.

Further in a finishing position following the start position, which canalso serve for control, optionally an outer intermediary layer and arubber stopper or the like are slipped onto the legs of the wirebracket, The intermediate layers, as well as the rubber stoppers can beapplied manually or in a suitable automated manner by the robot.

This way alternately a prepared stacking plate and a finished stackingplate are moved in a double timed step by means of the revolving chaininto a bag stack removal position assigned to the removal station,whereby each time the finished bag stack can be seized by the grip armof the robot which removes the bag stacks from the pin stacking conveyorand can be deposited in a packaging unit.

BRIEF DESCRIPTION OF THE DRAWING

Preferred embodiment examples of the invention are represented in thedrawing and subsequently closer explained. The drawing shows:

FIG. 1 a side view of a bag-producing machine with a pin stackingconveyor and a robot with a multifunctional hand,

FIG. 2 a top view of the machine shown in FIG. 1,

FIG. 3 a perspective representation of a single plastic bag,

FIG. 4 a corresponding representation of a bag stack consisting ofseveral plastic bags,

FIG. 5 a side view of a locking and straightening unit,

FIG. 6 the thereto pertaining top view,

FIG. 7 the locking and straightening unit in cooperation with abracket-feeding plate,

FIG. 8 a top view of two identical machines arranged next to each other,

FIG. 9 a top view of machines designed to be the mirror image of eachother and arranged next to each other,

FIG. 10 a frontal view of a multifunctional hand of the robot,

FIG. 11 the thereto pertaining side view,

FIG. 12 a top view on the multifunctional hand,

FIG. 13 a part of the multifunctional hand,

FIG. 14 a part of the transfer device with a bracket magazine and astraightening and feeding tong between the multifunctional hand of therobot and the bracket magazine,

FIG. 15 a top view on four machines arranged next to each other with acommon transport belt designed as a an elevated transport chain,

FIG. 16 the thereto pertaining frontal view,

FIG. 17 a top view on a machine with the interlocking of the bagpackages in the area of the pin stacking conveyor and discharge withinthe boxing station,

FIG. 18 a plastic bag with interlocking locations produced by fusion,

FIG. 19 a boxing station on an enlarged scale,

FIG. 20 a part of a pin stacking conveyor with a collection device,

FIG. 21 a cross section through a bag stack held together by a wirebracket on an enlarged scale.

WAYS TO IMPLEMENT THE INVENTION

In FIG. 1 a bag-producing machine 1 is schematically represented, whichis built and equipped for producing plastic bags, particularly so-calledautomatic plastic bags. From an unwinding stand not shown in the drawinga thermoplastic foil web, which can be for instance a tubular foil web,is unwound from a winding roll. Inside the bag-producing machine 1, thetubular foil web is guided over a not represented drive and tensioningrollers. By means of a hole-punching device also not shown in thedrawing and a crosscutting-welding device, the bags 2 (FIG. 3) can beproduced in a manner which is subsequently closer described. Thecrosscutting-welding device is followed by a transfer device 3, which inturn is followed by a pin stacking conveyor 4 with a stepwise revolvingpin stacking chain 5. The individual plastic bags collected on the pinstacking conveyor can be collected to form package-like bag stacks 6, asindicated in FIG. 1. Such a bag stack 6 is closer illustrated in FIG. 4.Before we discuss this any further, in FIG. 3 it is shown that eachindividual plastic bag 2 as a so-called automatic bag has in the area ofthe filling opening 7 an unilaterally projecting upper flap 8, whereintwo suspension holes 9 have been punched, to which at a short distancein the direction of the outer edge 11 of the upper flap 8 tear-offperforation slots 12 have been assigned.

After a bag stack has been formed, on the pin stacking chain 5 the bagstacks 6 are transported to a discharge station 13 located at the end ofthe pin stacking conveyor 4. In the area of the discharge station 13 asupport frame 14 is arranged, which has an upper mounting plate 15, onwhich a robot 16 with a gripping arm 10 and a grip hand 17 are rigidlymounted. The robot 16 has a total of 6 rotation axes and is capable toremove the closest bag stack 6 from the pin stacking chain 5 by means ofthe grip hand 17 and to lift it at least to the level of the mountingplate 15 of the support frame 14. On the mounting plate 15 a rotatablydriven plate carousel is arranged, which basically has four deflectionrollers 18, one of which is being driven and around which a drive belt19 is guided. On the revolving drive belt 19 holding plates 21 arearranged, on each of them a wire bracket 23 is clampingly held via aclamping element 22 (FIG. 7). While the plate carousel is revolving, theholding plates 21 with the wire brackets 23 reach the area of a lockingand straightening unit 24, as closer described in FIGS. 5 to 7, fastenedon the mounting plate 15 of the support frame 14. As can be seenespecially from FIG. 6, the locking and straightening unit 24 has aprolonged leg 25, which at its frontal end consists of two leg clips 26with a clamping element 27 arranged on one of the leg clips. The lockingand straightening unit 24 can be adjusted via an adjustment mechanismnot explained in detail, so that the leg clips 26 traverse the one legof the wire bracket 23 fastened to the holding plate 21 fir over theclamping element 22. In connection with an additional angled element 28screwed to the holding plate 21 and a spring element 32 supportedagainst the rod element 31, an additional locking and straightening ofthe wire bracket 23 is achieved.

As soon as the wire bracket 23 is fixed this way, the bag stack 6removed from the pin stacking chain 5 is placed on the projecting legsof the wire bracket 23 via suspension holes 9. To the extent that it isrequired or desired, prior to the removal of the bag stack 6 also apaper strip, respectively an intermediate paper layer 33 can be insertedin the locking and straightening unit 24. A supply container for suchintermediate paper layers 33 can be for instance mounted on the mountingplate 15 of the support frame 14, as shown in FIG. 2. The intermediatepaper layer can of course also be arranged laterally next to the supportframe 14. After the bag stack 6 has been impaled on the settled wirebracket 23, again, if required, a paper strip, respectively anintermediate paper layer 33 and finally a safety plate 34 in the form ofa rubber stopper or the like are applied. These rubber stoppers 34 arefor instance stored in a spiral-shaped vibratory hopper 35, namely alsoon the mounting plate 15 or next to it. Within the framework of aquality control, the bag package interlocked this way with the wirebrackets and the applied safety plates, which are again pressed togetherby the operator, are examined as to the correct position of each bag andthan carried away either manually of via the grip hand 17 of the robot16 and packaged for instance in a cardboard box.

In the robot arrangement according to the invention, the order in whichthe machines are arranged is not very important, i.e. besides onemachine, it is also possible for one operator to serve two identicalmachines or two machines arranged in a mirror-image manner, as shownschematically in FIGS. 8 and 9.

In order to meet these requirements as best as possible, the design ofthe grip hand 17 of the robot is decisive. In FIGS. 10 to 13, thetong-like grip arm in the form of a multifunctional hand 17 isrepresented in detail. The multifunctional hand is actuated by acylinder-piston unit 36, which is swingably supported at 37 on theoutrigger of the robot 16. The cylinder-piston unit 36 rests on anangled piece 38, on which a substantially trapezoidal mounting plate 39is fastened. The mounting plate 39 made preferably of sandwich aluminumhas in its frontal area two spaced-apart guide bars 41, wherein acrossbeam 43 is axially displaceably supported via a guide element 42.The crossbeam 43 has a cross section profile of multiple T-shapedgrooves. In the individual profile grooves, on the one hand the guideelement 42, and on the other hand a ram 44 of the cylinder-piston unit36 are located, further on the frontal side one or two L-shaped clampingbars 45 and on the underside angled catch pins 46, the distance betweenthem corresponding to the distance between the suspension holes 9 in theplastic bags 2. Finally on the multifunctional hand 17 also wire bracketholders 47 can be provided, whose purpose will be further described. Incooperation with the upper clamping bar 45, a lower clamping bar 48 isfastened to the lower end of the mounting plate 39. Both clamping barscan be provided with a plastic lining 49, 51. On the rear side of themounting plate, two suction cups 52 are arranged in pairs for handlingthe above-mentioned safety plates 34, as well as two suction funnels 53for the above-mentioned paper strips, respectively intermediate paperlayers 33. As indicated in FIG. 13, the suction cups 52 are connectedvia a channel system 54 with a negative pressure source not shown in thedrawing. The same applies also to the suction funnels 53. Alternately,the two suction cups 52 can perform both functions.

The multifunctional hand 17 of the robot 16 works in detail as follows:In order to receive paper strips, respectively intermediate paper layers33, the multifunctional hand 17 is brought into the correspondingposition by means of the robot control, so that after suction air isapplied in the suction funnels 53, from the paper storage anintermediate paper layer can be removed. The intermediate paper layer isthen placed on a wire bracket 23 held in the correct position. For thispurpose the suction funnels 53 are shortly impacted with blowing air.Afterwards a bag stack is removed from the pin stacking conveyor 4 andsuspended from the wire bracket held in the locking and straighteningdevice 24. After that a further paper strip, respectively intermediatepaper layer 33 is again taken up by the robot, respectively by itsmultifunctional hand, and placed on the wire bracket 23. Finally bymeans of the suction cups the safety plates, respectively rubberstoppers 34 are taken up either separately or in pairs and pressed ontothe free legs of the wire bracket 23. In the next position of thetransport carousel, the bag package is examined by the operator,corrected if required, and manually removed from the holder, whereby therubber stoppers are again firmly pressed on and finally the bag packageis deposited in a box. If necessary, it is also possible to provide anautomated discharge by the robot.

In the FIGS. 14 to 16, an arrangement is shown which is different fromthe aforedescribed embodiment example in the sense that here the wirebrackets 23 are lodged in a bracket magazine 55, which is not closerdescribed. Between the bracket magazine 55 and the robot 16, astraightening and feeding tong 56 is arranged, which is pivotallysupported about a point indicated at 57. By means of this straighteningand feeding tong, wire brackets 23 can be removed from a bracketmagazine 55 and brought into such a position that with the assistance ofthe mutifunctional hand 17 of the robot 16 a bag stack 6 can be slippedonto the prepared wire bracket 23. After this is done, the wire bracketis released from the feeding and straightening tong 56, and with the aidof the robot 16 is transferred to an elevated transport belt in the formof an elevated transport chain 58. This way it is possible withoutfurther ado to arrange several machines, for instance four machines oneafter the other, as shown in FIG. 15, having a common transport belt 58.Each machine is equipped with its own robot 16 and each machine has itsown bracket magazine. Thereby each bracket magazine has a feeding,straightening and locking tong 56 which fits the width of the brackets.In order to keep the transfer and further transport of the wire bracketstrouble-free, the already mentioned wire bracket holders 47 are providedon the multifunctional hand.

When the interlocking by means of wire brackets 23 is supposed to beeliminated, then another method is used. In this case the bag stacks 6are interlocked already within the range of the pin stacking conveyor 4in a further described manner. The bag stacks interlocked this way canbe deposited in a cardboard box by means of the robot 16. This method iscloser described with the aid of FIGS. 17 to 19. In the station 4.1 ofthe pin stacking conveyor 4 the bag stacking takes place in the knownmanner. In the station 4.2 the interlocking of the stacked bags into bagstacks is performed by means of an interlocking device known per sethrough fusion. A configuration as shown in FIG. 18 can for instance beused for interlocking. By means of glow plugs the interlocking of thebag stack is performed in a perforated marginal area 59, more precise inthe area of a preferably prepunched hole 61. In the stations 4.3, 4.4,4.5 either a manual or an automated quality control takes place, whosedetails are here of no interest. It is decisive that after the qualitycontrol, by means of the multifunctional hand 17 of the robot 16, thebag package is removed from the pin stacking conveyor 4 and finallybrought to a discharge station, respectively a boxing station 62. Thereby means of the robot 16 the respective bag package is deposited in abox 69, which—as indicated by the arrow 63—is moved from the left to theright until it reaches the actual delivery position, whereafter the boxis displaced in the direction of the arrow 64 and finally brought into adelivery position in the direction of arrow 65. The discharge of the bagstack is shown in detail in FIG. 19. It can be seen that the box station62 has a height-adjustable lifting table 66. Furthermore laterallyadjustable support wall 67, 68 are part thereof, which can function ashinges at least on one side, so that the empty boxes can be slid intothe discharge station. Due to the adjustable support walls 67, 68, thedevice can be adjusted to the various sizes of the boxes 69. In theupper area of the box station 62, a filling chute 71 is provided,wherein by means of schematically shown displacement mechanisms 72,partitions 73, 74 can be slid from the side into the filling chute 71,and again extracted therefrom. The inserted position is represented withthe aid of the upper partitions 73, 74, while the extracted position ofthe upper partitions 73, 74 is shown in the lower position. Thepartitions have the task to insure that during the filling of the bagstacks, the drop distance is not too big. For the same purpose the boxcan be raised via the lifting table 66, as indicated in broken lines.Finally at the lower end of the filling chute 71, it is also possible toprovide release flaps 75, in order to further simplify the emptying ofthe chute. The arrow 76 indicates a compression ram, which presses thebags downwards in order to remove possible air lodged between theindividual bags, thereby insuring a perfect packaging of the bag stack 6in the box 69.

In the illustration of FIG. 20, the collection device has a fillingstation 80 with a receiving position 81, as well as control and/orservice station 82, and finally the discharge, respectively removalstation 13 on the opposite side of the drive belt 19.

In the area of the removal station 13, a packaging device 83 with a bagstack removal position 84, corresponding to the above-described boxingstation 62, is arranged. On a feeding table 90 the packaged units, suchthe boxes 69, can be supplied. Along an intermediate table 85, the boxesfilled with bag stacks can be carried away over a roller table 86.Between the packaging station 83 and the pin stacking conveyor 4 aseparate suspension device 87 is arranged, which has a receiving stand88 on which bag stacks not produced in an orderly manner can besuspended by means of the robot 16. For this purpose the robot can becontrolled by a control device not shown in the drawing of the pinstacking conveyor, for instance by a light barrier/photoelectric cell orthe like.

A bag stack 6 of the here-described kind is represented in detail inFIG. 21. It consists of the actual bag stack 6, which in turn consistsof a multitude of separate plastic bags, as well as of the innerintermediate layer 33 and the outer intermediate layer 33. Theaforementioned parts are kept together by the already mentioned wirebrackets 23 and finally also by rubber stoppers 34 or the like. Inprinciple the bag stacks can also consist of interlocked bags, as knownper se. In this case the wire bracket serves merely as a transportelement.

The device shown in FIG. 20 works as follows:

The robot 16 equipped for instance with a total of six axes of rotationis capable to remove a bag stack 6 by means of the multifunctional hand17 from the stacking pins 5′ of the pin stacking chain 5, and to movethis bag stack into the receiving position 81 of the filling station 80.There the bag stack is suspended in stacking plate 21 equipped with awire bracket 23, in a manner with is closer described further down. Inorder to facilitate the removal of a suspended bag stack from the pinstacking conveyor, an upwards swinging flap can be provided in thisarea, so that the bag stack can be removed in a substantially horizontalposition. In a start position 89 of the control and/or service station82, which follows the receiving position 81 in a timed step, at thebeginning of a work cycle at first a wire bracket 23 is suspended in theholding element of the stacking plate 21 in this position at the timeand at the same time the inner intermediate layer 33 is placed on thewire bracket. Then the revolving chain 19 is automatically moved furtherin a double timed step. As a result the aforedescribed bag stack in thereceiving position 81 has reached a finishing position 91 of the controland/or service unit 82 where the operator applies the outer intermediatelayer 33 and the rubber plug 34 shown in FIG. 21. While the startposition 89 shows a prepared stacking plate 21, from the finishingposition 91 which follows in a single timed step, a finished stackingplate can be seen. After a new bag stack is taken up by the pin stackingconveyor 4, the prepared stacking plate and the finished stacking platereach the bag removal position 84 of the removal station 13 alternatelyin succession one after the other where the respective finished bagstacks are removed by the grip arm 10, respectively the multifunctionalhand 17 of the robot 16 and deposited for instance in the box 69. Thefollowing empty stacking plate of the bag receiving position 84, whichin a single timed step is preceded by a prepared stacking plate 21 in anintermediate station 92, is then moved in double timed step until itreaches a middle empty position 93 in the area of the pin stackingconveyor 4, in order to be again in the start position 89 after thefollowing double timed step.

It is self-understood that the invention is not limited only to theillustrated embodiment examples, but also allows for modification withinthe claims, so for instance it is possible without further ado to usethe robot according to the invention also in other types of machines,such as for instance machines for shirt-carrying bags, which alsoproduce bag packages and have to be subsequently packaged. Further thedeflection rolls of the plate carousel can be replaced by a wheel-shapedor circular plate.

What is claimed is:
 1. An apparatus for producing bags and deliveringbags in stacks, said apparatus comprising: a bag-making machine having acrosscut-welding station for welding seams in a double-layer plasticfoil web and separating plastic bags therefrom, and a stamping stationfor producing stacking holes in said plastic bags; a pin stackingconveyor having a pin stacking chain movable in steps along saidbag-making machine whereby stacks of said bags are formed on respectivepairs of pins of said chain and said stacks are carried by said chain toan end of said pin stacking conveyor; a single six-axis robot located atsaid end of said pin stacking conveyor and having a program-controlledmultifunctional gripper hand and controlled as a function of movementsof said pin stacking chain for all manipulations of each bag stack atsaid end of said conveyor; and a bracket-fixing andbracket-straightening device located within a range of motion of saidhand for orienting wire brackets adapted to engage in holes of saidbags, said gripper hand engaging said stacks and inserting the bracketsinto holes of said stacks and removing said stacks from said conveyorfor subsequent packaging of said stacks with respective brackets engagedtherein.
 2. The apparatus defined in claim 1 wherein said robot ismounted above a rotation plane of the pin-stacking chain on a supportframe located downstream of said conveyor and receiving saidbracket-fixing and bracket-straightening device and means for applyingsafety members to said bracket and paper layers to said stacks.
 3. Theapparatus defined in claim 1 wherein said multifunctional gripper handhas first and second clamping bars displaceable one toward the other,one of said clamping bars having at a lower end a mounting plate and theother of said clamping bars being fastened on a crossbeam formed withgrooves for guide elements mounted on said mounting plate.
 4. Theapparatus defined in claim 3, further comprising catch pins on saidcrossbeam angled obliquely forwardly of said hand, said clamping barshaving clamping surfaces at least partly provided with an elasticlining.
 5. The apparatus defined in claim 4 wherein a holding deviceoperating with negative pressure is provided on a side of said mountingplate for engagement with a safety member applicable to the wire bracketof a stack.
 6. The apparatus defined in claim 1, further comprising abracket magazine for supplying the wire brackets to said device.
 7. Theapparatus defined in claim 1, further comprising a transport belt fordelivering the stacks to a packaging machine.
 8. The apparatus definedin claim 1, further comprising a boxing station within a range of motionof said gripper hand for receiving cardboard boxes in which said handdeposits said stacks.
 9. The apparatus defined in claim 1 wherein acollection device is provided within a range of motion of said gripperhand and includes a timed-revolving drive belt on which spaced-apartstacking plates each with a holding element, are fastened.
 10. Theapparatus defined in claim 9 wherein said drive belt is guided aboutguide rollers located at corners of a rectangle.
 11. The apparatusdefined in claim 1, further comprising a photoelectric unit on saidpin-stacking conveyor for examination of finished bag stacks.